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Fulltext Sarcocystosis among wild captive and zoo animals in Malaysia

Latif B, Vellayan S, Omar E, Abdullah S, Mat Desa N

Korean J Parasitol, 2010 Sep;48(3):213-7.
PMID: 20877499 DOI: 10.3347/kjp.2010.48.3.213

Sarcocystis sp. infection was investigated in 20 necropsied captive wild mammals and 20 birds in 2 petting zoos in Malaysia. The gross post-mortem lesions in mammals showed marbling of the liver with uniform congestion of the intestine, and for birds, there was atrophy of the sternal muscles with hemorrhage and edema of the lungs in 2 birds. Naked eye examination was used for detection of macroscopic sarcocysts, and muscle squash for microscopic type. Only microscopically visible cysts were detected in 8 animals and species identification was not possible. Histological examination of the sections of infected skeletal muscles showed more than 5 sarcocysts in each specimen. No leukocytic infiltration was seen in affected organs. The shape of the cysts was elongated or circular, and the mean size reached 254 x 24.5 µm and the thickness of the wall up to 2.5 µm. Two stages were recognized in the cysts, the peripheral metrocytes and large numbers of crescent shaped merozoites. Out of 40 animals examined, 3 mammals and 5 birds were positive (20%). The infection rate was 15% and 25% in mammals and birds, respectively. Regarding the organs, the infection rate was 50% in the skeletal muscles followed by tongue and heart (37.5%), diaphragm (25%), and esophagus (12.5%). Further ultrastructural studies are required to identify the species of Sarcocystis that infect captive wild animals and their possible role in zoonosis.

Matched MeSH terms: Muscle, Skeletal/pathology
Muscle synergies during incremental rowing VO2max test of collegiate rowers and untrained subjects

Shaharudin S, Agrawal S

J Sports Med Phys Fitness, 2016 Sep;56(9):980-9.
PMID: 25732319

BACKGROUND: The purpose of this study was to evaluate the muscle synergies during incremental rowing VO2 max Test of collegiate rowers and untrained subjects. As a power endurance sport, high aerobic capacity was one of the determinants of rowing performance. The modulation of muscle recruitment patterns following specific physiological demands was an indication of the robustness of muscle synergies composition which was overlooked in previous studies.
METHODS: Ten male collegiate rowers and physically active untrained subjects were recruited. Muscle synergies were extracted from 16 rowing-specific muscles using Principal Component Analysis with varimax rotation. Incremental rowing VO2 max Test was performed on slides ergometer (SE). Rowing performance and physiological variables were analyzed.
RESULTS: Rowers exerted greater power output, more energy expenditure and better rowing economy compared to untrained subjects. Rowers preferred to row slower with longer strokes compared to the untrained subjects. Three muscle synergies with high indices of similarity of waveform patterns were extracted in both groups. Significant association was found between muscle synergies and rowing economy.
CONCLUSIONS: The findings of this study showed that muscle synergies were robust during aerobic-dominant activity for collegiate rowers and untrained subjects. Rowers and coaches could utilize the findings by emphasizing on muscle coordination training, which may enhance the rowing economy.

Matched MeSH terms: Muscle, Skeletal/physiology*
Laminated pedicled latissimus dorsi myocutaneous flap for single-stage reconstruction of a composite anterior neck and tracheal defect

Wu LY, Halim AS, Sain AH

J Otolaryngol, 2005 Feb;34(1):69-72.
PMID: 15966482
Matched MeSH terms: Muscle, Skeletal/transplantation*
Postprandial increases in nitrogenous excretion and urea synthesis in the giant mudskipper Periophthalmodon schlosseri

Ip YK, Lim CK, Lee SL, Wong WP, Chew SF

J Exp Biol, 2004 Aug;207(Pt 17):3015-23.
PMID: 15277556

The objective of this study was to determine the effects of feeding on the excretory nitrogen (N) metabolism of the giant mudskipper, Periophthalmodon schlosseri, with special emphasis on the role of urea synthesis in ammonia detoxification. The ammonia and urea excretion rates of P. schlosseri increased 1.70- and 1.92-fold, respectively, within the first 3 h after feeding on guppies. Simultaneously, there were significant decreases in ammonia levels in the plasma and the brain, and in urea contents in the muscle and liver, of P. schlosseri at 3 h post-feeding. Thus, it can be concluded that P. schlosseri was capable of unloading ammonia originally present in some of its tissues in anticipation of ammonia released from the catabolism of excess amino acids after feeding. Subsequently, there were significant increases in urea content in the muscle, liver and plasma (1.39-, 2.17- and 1.62-fold, respectively) at 6 h post-feeding, and the rate of urea synthesis apparently increased 5.8-fold between 3 h and 6 h. Increased urea synthesis might have occurred in the liver of P. schlosseri because the greatest increase in urea content was observed therein. The excess urea accumulated in the body at 6 h was completely excreted between 6 and 12 h, and the percentage of waste-N excreted as urea-N increased significantly to 26% during this period, but never exceeded 50%, the criterion for ureotely, meaning that P. schlosseri remained ammonotelic after feeding. By 24 h, 62.7% of the N ingested by P. schlosseri was excreted, out of which 22.6% was excreted as urea-N. This is the first report on the involvement of increased urea synthesis and excretion in defense against ammonia toxicity in the giant mudskipper, and our results suggest that an ample supply of energy resources, e.g. after feeding, is a prerequisite for the induction of urea synthesis. Together, increases in nitrogenous excretion and urea synthesis after feeding effectively prevented a postprandial surge of ammonia in the plasma of P. schlosseri as reported previously for other fish species. Consequently, contrary to previous reports, there were significant decreases in the ammonia content of the brain of P. schlosseri throughout the 24 h period post-feeding, accompanied by a significant decrease in brain glutamine content between 12 h and 24 h.

Matched MeSH terms: Muscle, Skeletal/metabolism
Jumping in lantern bugs (Hemiptera, Fulgoridae)

Burrows M, Ghosh A, Sutton GP, Yeshwanth HM, Rogers SM, Sane SP

J Exp Biol, 2021 12 01;224(23).
PMID: 34755862 DOI: 10.1242/jeb.243361

Lantern bugs are amongst the largest of the jumping hemipteran bugs, with body lengths reaching 44 mm and masses reaching 0.7 g. They are up to 600 times heavier than smaller hemipterans that jump powerfully using catapult mechanisms to store energy. Does a similar mechanism also propel jumping in these much larger insects? The jumping performance of two species of lantern bugs (Hemiptera, Auchenorrhyncha, family Fulgoridae) from India and Malaysia was therefore analysed from high-speed videos. The kinematics showed that jumps were propelled by rapid and synchronous movements of both hind legs, with their trochantera moving first. The hind legs were 20-40% longer than the front legs, which was attributable to longer tibiae. It took 5-6 ms to accelerate to take-off velocities reaching 4.65 m s-1 in the best jumps by female Kalidasa lanata. During these jumps, adults experienced an acceleration of 77 g, required an energy expenditure of 4800 μJ and a power output of 900 mW, and exerted a force of 400 mN. The required power output of the thoracic jumping muscles was 21,000 W kg-1, 40 times greater than the maximum active contractile limit of muscle. Such a jumping performance therefore required a power amplification mechanism with energy storage in advance of the movement, as in their smaller relatives. These large lantern bugs are near isometrically scaled-up versions of their smaller relatives, still achieve comparable, if not higher, take-off velocities, and outperform other large jumping insects such as grasshoppers.

Matched MeSH terms: Muscle, Skeletal
Effects of acute supplementation of caffeine on cardiorespiratory responses during endurance running in a hot & humid climate

Ping WC, Keong CC, Bandyopadhyay A

Indian J Med Res, 2010 Jul;132:36-41.
PMID: 20693587

Athletes in Malaysia need to perform in a hot and humid climate. Chronic supplementation of caffeine on endurance performance have been studied extensively in different populations. However, concurrent research on the effects of acute supplementation of caffeine on cardiorespiratory responses during endurance exercise in the Malaysian context especially in a hot and humid environment is unavailable.

Matched MeSH terms: Muscle, Skeletal/drug effects*
Beneficial effects of ginger (Zingiber officinale) on carbohydrate metabolism in streptozotocin-induced diabetic rats

Abdulrazaq NB, Cho MM, Win NN, Zaman R, Rahman MT

Br J Nutr, 2012 Oct;108(7):1194-201.
PMID: 22152092

Zingiber officinale (ZO), commonly known as ginger, has been traditionally used in the treatment of diabetes mellitus. Several studies have reported the hypoglycaemic properties of ginger in animal models. The present study evaluated the antihyperglycaemic effect of its aqueous extract administered orally (daily) in three different doses (100, 300, 500 mg/kg body weight) for a period of 30 d to streptozotocin (STZ)-induced diabetic rats. A dose-dependent antihyperglycaemic effect revealed a decrease of plasma glucose levels by 38 and 68 % on the 15th and 30th day, respectively, after the rats were given 500 mg/kg. The 500 mg/kg ZO significantly (P<0·05) decreased kidney weight (% body weight) in ZO-treated diabetic rats v. control rats, although the decrease in liver weight (% body weight) was not statistically significant. Kidney glycogen content increased significantly (P<0·05) while liver and skeletal muscle glycogen content decreased significantly (P<0·05) in diabetic controls v. normal controls. ZO (500 mg/kg) also significantly decreased kidney glycogen (P<0·05) and increased liver and skeletal muscle glycogen in STZ-diabetic rats when compared to diabetic controls. Activities of glucokinase, phosphofructokinase and pyruvate kinase in diabetic controls were decreased by 94, 53 and 61 %, respectively, when compared to normal controls; and ZO significantly increased (P<0·05) those enzymes' activities in STZ-diabetic rats. Therefore, the present study showed that ginger is a potential phytomedicine for the treatment of diabetes through its effects on the activities of glycolytic enzymes.

Matched MeSH terms: Muscle, Skeletal/drug effects; Muscle, Skeletal/metabolism
Fulltext Sarcocystis nesbitti infection in human skeletal muscle: possible transmission from snakes

Lau YL, Chang PY, Tan CT, Fong MY, Mahmud R, Wong KT

Am J Trop Med Hyg, 2014 Feb;90(2):361-4.
PMID: 24420776 DOI: 10.4269/ajtmh.12-0678

Sarcocystis nesbitti is an intracellular protozoan parasite found as sarcocysts within muscle fibers of intermediate hosts (monkey and baboon). The definitive host is suspected to be the snake. We report two cases from a larger cohort of 89 patients who had fever, headache, and generalized myalgia after a trip to Pangkor Island, Malaysia. Sarcocysts were detected in skeletal muscle biopsy specimens by light and electron microscopy from these two patients. DNA sequencing based on the 18S ribosomal DNA region identified the Sarcocystis species as S. nesbitti. We also identified S. nesbitti sequences in the stools of a snake (Naja naja). Phylogenetic analysis showed that these sequences form a cluster with most of the other known Sarcocystis species for which the snake is a definitive host. We believe these two patients were likely to have symptomatic acute muscular sarcocystosis after S. nesbitti infection that may have originated from snakes.

Matched MeSH terms: Muscle, Skeletal/parasitology*
An outbreak of acute eosinophilic myositis attributed to human Sarcocystis parasitism

Arness MK, Brown JD, Dubey JP, Neafie RC, Granstrom DE

Am J Trop Med Hyg, 1999 Oct;61(4):548-53.
PMID: 10548287

Seven members of a 15-man U.S. military team that had operated in rural Malaysia developed an acute illness consisting of fever, myalgias, bronchospasm, fleeting pruritic rashes, transient lymphadenopathy, and subcutaneous nodules associated with eosinophilia, elevated erythrocyte sedimentation rate, and elevated levels of muscle creatinine kinase. Sarcocysts of an unidentified Sarcocystis species were found in skeletal muscle biopsies of the index case. Albendazole ameliorated symptoms in the index case; however, his symptoms persisted for more than 5 years. Symptoms in 5 other men were mild to moderate and self-limited, and 1 team member with laboratory abnormalities was asymptomatic. Of 8 team members tested for antibody to Sarcocystis, 6 were positive; of 4 with the eosinophilic myositis syndrome who were tested, all were positive. We attribute this outbreak of eosinophilic myositis to accidental tissue parasitism by Sarcocystis.

Matched MeSH terms: Muscle, Skeletal/parasitology*; Muscle, Skeletal/pathology
Platelet-rich plasma injections for the treatment of hamstring injuries: a randomized controlled trial

A Hamid MS, Mohamed Ali MR, Yusof A, George J, Lee LP

Am J Sports Med, 2014 Oct;42(10):2410-8.
PMID: 25073598 DOI: 10.1177/0363546514541540

BACKGROUND: A hamstring injury is one of the most common types of injury affecting athletes. Despite this, the optimal management of hamstring muscle injuries is not yet defined. The effect of autologous platelet-rich plasma (PRP) therapy on the recovery of hamstring injuries is unclear.
PURPOSE: To investigate the effect of a single PRP injection in the treatment of grade 2 hamstring muscle injuries.
STUDY DESIGN: Randomized controlled trial; Level of evidence, 2.
METHODS: Twenty-eight patients diagnosed with an acute hamstring injury were randomly allocated to autologous PRP therapy combined with a rehabilitation program or a rehabilitation program only. The primary outcome of this study was time to return to play. In addition, changes in pain severity and pain interference scores over time were examined.
RESULTS: Patients in the PRP group achieved full recovery significantly earlier than controls (P = .02). The mean time to return to play was 26.7 ± 7.0 days and 42.5 ± 20.6 days for the PRP and control groups, respectively (t(22) = 2.50, P = .02). [corrected]. Significantly lower pain severity scores were observed in the PRP group throughout the study. However, no significant difference in the pain interference score was found between the 2 groups.
CONCLUSION: A single autologous PRP injection combined with a rehabilitation program was significantly more effective in treating hamstring injuries than a rehabilitation program alone.
KEYWORDS: management; muscle injury; platelet-rich plasma (PRP); return to play

Matched MeSH terms: Muscle, Skeletal/injuries*
Evaluation of repetitive isometric contractions on the heads of triceps brachii muscle during grip force exercise

Ali MA, Sundaraj K, Ahmad RB, Ahamed NU, Islam MA, Sundaraj S

Technol Health Care, 2014;22(4):617-25.
PMID: 24990168 DOI: 10.3233/THC-140833

Normally, surface electromyography electrodes are used to evaluate the activity of superficial muscles during various kinds of voluntary contractions of muscle fiber. The objective of the present study was to investigate the effect of repetitive isometric contractions on the three heads of the triceps brachii muscle during handgrip force exercise.

Matched MeSH terms: Muscle, Skeletal/physiology
Information-based analysis of the relation between human muscle reaction and walking path

Kamal SM, Dawi NBM, Sim S, Tee R, Nathan V, Aghasian E, et al.

Technol Health Care, 2020;28(6):675-684.
PMID: 32200366 DOI: 10.3233/THC-192034

BACKGROUND: Walking is one of the important actions of the human body. For this purpose, the human brain communicates with leg muscles through the nervous system. Based on the walking path, leg muscles act differently. Therefore, there should be a relation between the activity of leg muscles and the path of movement.
OBJECTIVE: In order to address this issue, we analyzed how leg muscle activity is related to the variations of the path of movement.
METHOD: Since the electromyography (EMG) signal is a feature of muscle activity and the movement path has complex structures, we used entropy analysis in order to link their structures. The Shannon entropy of EMG signal and walking path are computed to relate their information content.
RESULTS: Based on the obtained results, walking on a path with greater information content causes greater information content in the EMG signal which is supported by statistical analysis results. This allowed us to analyze the relation between muscle activity and walking path.
CONCLUSION: The method of analysis employed in this research can be applied to investigate the relation between brain or heart reactions and walking path.

Matched MeSH terms: Muscle, Skeletal
Morphometric analysis and surgical adequacy of palmaris longus as a tendon graft. A systematic review of cadaveric studies

Yammine K, Erić M

Surg Radiol Anat, 2020 Mar;42(3):259-267.
PMID: 31741040 DOI: 10.1007/s00276-019-02381-x

INTRODUCTION: The tendon of the palmaris longus is commonly used as a tendon graft in many reconstructive surgeries. Easy to access and at proximity to the hand, the palmaris longus tendon is considered as the optimal tendon source for hand reconstructive surgery. However, and besides its inconsistency, the size of the palmaris longus tendon is reported to show variability. The aim of this study is to look for the surgical adequacy of the palmaris longus tendon by conducting a quantitative synthesis on its length and width in human populations and its correlation with the forearm length.
METHODS: Twenty-four studies met the inclusion criteria including 1761 cadaveric limbs.
RESULTS: The results were as following: (a) the mean palmaris longus tendon length was of 13.9 ± 2.6 cm, (b) the mean ratio palmaris longus tendon length/forearm length was of 0.545 ± 0.06, (c) the weighted correlation value was of 0.686, and (d) the mean palmaris longus tendon width was of 4.0 ± 1.7 mm. Only five studies reported a palmaris longus tendon length of more than 15 cm. The palmaris longus tendon length was shown to vary between ancestries; the Japanese had the shortest while Malaysian the longest palmaris longus tendons. All studies but one reported a palmaris longus tendon mean width of more than 3 mm where the minimal mean palmaris longus tendon width was of 2.5 mm.
CONCLUSION: While the requested length depends on the recipient site and/or type of reconstructive surgery, the palmaris longus tendon often met the required diameter for grafting. Our review demonstrated that while palmaris longus length varies between ancestries, its width is often adequate for grafting. In addition, the forearm length could be a good predictor of palmaris longus tendon length; such correlation could assist surgeons when planning to use palmaris longus tendon as a graft source.

Matched MeSH terms: Muscle, Skeletal/anatomy & histology*; Muscle, Skeletal/transplantation
Synthesis and characterization of silver nanoparticles using fruit extract of Momordica cymbalaria and assessment of their in vitro antimicrobial, antioxidant and cytotoxicity activities

Swamy MK, Akhtar MS, Mohanty SK, Sinniah UR

Spectrochim Acta A Mol Biomol Spectrosc, 2015 Dec 5;151:939-44.
PMID: 26186612 DOI: 10.1016/j.saa.2015.07.009

Plant mediated synthesis of nanoparticles has been considered as green route and a reliable technique for the synthesis of nanoparticles due to its eco-friendly approach. In this study, we report a simple and eco-friendly approach for the synthesis of silver nanoparticles (AgNPs) using methanolic Momordica cymbalaria fruit extract as reducing agent. The fruit extract of M. cymbalaria exposed to AgNO3 solution showed the change in color from green to light yellow at room temperature within 1h of incubation confirms the synthesis of AgNPs. UV-vis spectra analysis revealed that the synthesized AgNPs had a sharp surface plasmon resonance at around 450 nm, while, the X-ray Diffraction (XRD) patterns confirmed distinctive peaks indices to the crystalline planes of the face centered cubic silver. The Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) analysis results confirmed the presence of spherical shaped AgNPs by a huge disparity in the particle size distribution with an average size of 15.5 nm. The synthesized AgNPs showed strong antibacterial activity against all the tested multidrug resistant human pathogenic bacterial strains and also exhibited highest free radical scavenging activity (74.2%) compared to fruit extract (60.4%). Moreover, both fruit extract and the synthesized AgNPs showed the cytotoxicity towards Rat L6 skeletal muscle cell line at different concentrations, but the highest inhibition percentage was recorded for AgNPs at concentration of 100 μg/ml.

Matched MeSH terms: Muscle, Skeletal
Fulltext Pattern of muscle injuries and predictors of return-to-play duration among Malaysian athletes

Mohamad Shariff HA, Ashril Y, Mohamed Razif MA

Singapore Med J, 2013 Oct;54(10):587-91.
PMID: 24154585

INTRODUCTION: The purpose of this study was to investigate the pattern of muscle injuries and the factors that predict the return-to-play duration among Malaysian athletes.

METHODS: This is a retrospective review of the case notes of athletes who attended the National Sports Institute Clinic in Malaysia. The medical records of athletes with muscle injury, diagnosed on clinical assessment and confirmed by diagnostic ultrasonography, were included for final analysis.

RESULTS: From June 2006 to December 2009, 397 cases of muscle injury were diagnosed among 360 athletes. The median age of the athletes with muscle injuries was 20.0 years. Muscle injuries were mostly diagnosed among national-level athletes and frequently involved the lower limb, specifically the hamstring muscle group. Nearly all of the athletes (99.2%) were treated conservatively. The median return-to-play duration was 7.4 weeks. Athletes who waited more than one week before seeking medical attention, those with recurrent muscle injuries and female athletes were significantly more likely (p < 0.05) to take more than six weeks before returning to the sport.

CONCLUSION: Grade 2 lower limb muscle injury was commonly diagnosed among national-level athletes in this study. The frequency of weekly physiotherapy sessions did not affect the return-to-play duration. Factors such as initial consultation at more than one week post injury, recurrent muscle injuries and female gender were significant predictors of return-to-play duration among Malaysian athletes. These predictive factors should be kept in mind during clinical assessment so as to aid in prognosticating recovery after muscle injury.

Matched MeSH terms: Muscle, Skeletal/injuries*; Muscle, Skeletal/physiopathology
Fulltext Multiple accessory structures in the upper limb of a single cadaver

Vollala VR, Nagabhooshana S, Bhat SM, Potu BK, Rakesh V

Singapore Med J, 2008 Sep;49(9):e254-8.
PMID: 18830534

The arterial and muscular variations of the upper limbs are common but important with regard to surgical approaches. Even though anomalies of the coracobrachialis muscle are rare, anatomical variations of the biceps brachii, existence of the accessory muscles in the forearm and persistent median artery are known and well documented. During routine dissection, we observed some important anatomical variations in a 50-year-old male cadaver. The variations were unilateral. The anomalies were: third head for biceps brachii muscle, an accessory belly for coracobrachialis muscle crossing the median nerve and brachial vessels and continuing with the medial head of triceps brachii muscle to be inserted to the olecranon process (coracoulnaris), a persistent median artery and an additional muscle in the anterior compartment of forearm. Although there are individual reports about these variations, the combination of these variations in one cadaver has not previously been described in the literature. Awareness of these variations is necessary to avoid complications during radiodiagnostic procedures or surgeries in the upper limb.

Matched MeSH terms: Muscle, Skeletal/abnormalities*; Muscle, Skeletal/pathology*
Fulltext Mechanomyographic parameter extraction methods: an appraisal for clinical applications

Ibitoye MO, Hamzaid NA, Zuniga JM, Hasnan N, Wahab AK

Sensors (Basel), 2014;14(12):22940-70.
PMID: 25479326 DOI: 10.3390/s141222940

The research conducted in the last three decades has collectively demonstrated that the skeletal muscle performance can be alternatively assessed by mechanomyographic signal (MMG) parameters. Indices of muscle performance, not limited to force, power, work, endurance and the related physiological processes underlying muscle activities during contraction have been evaluated in the light of the signal features. As a non-stationary signal that reflects several distinctive patterns of muscle actions, the illustrations obtained from the literature support the reliability of MMG in the analysis of muscles under voluntary and stimulus evoked contractions. An appraisal of the standard practice including the measurement theories of the methods used to extract parameters of the signal is vital to the application of the signal during experimental and clinical practices, especially in areas where electromyograms are contraindicated or have limited application. As we highlight the underpinning technical guidelines and domains where each method is well-suited, the limitations of the methods are also presented to position the state of the art in MMG parameters extraction, thus providing the theoretical framework for improvement on the current practices to widen the opportunity for new insights and discoveries. Since the signal modality has not been widely deployed due partly to the limited information extractable from the signals when compared with other classical techniques used to assess muscle performance, this survey is particularly relevant to the projected future of MMG applications in the realm of musculoskeletal assessments and in the real time detection of muscle activity.

Matched MeSH terms: Muscle, Skeletal/physiopathology*
Fulltext The effectiveness of FES-evoked EMG potentials to assess muscle force and fatigue in individuals with spinal cord injury

Ibitoye MO, Estigoni EH, Hamzaid NA, Wahab AK, Davis GM

Sensors (Basel), 2014;14(7):12598-622.
PMID: 25025551 DOI: 10.3390/s140712598

The evoked electromyographic signal (eEMG) potential is the standard index used to monitor both electrical changes within the motor unit during muscular activity and the electrical patterns during evoked contraction. However, technical and physiological limitations often preclude the acquisition and analysis of the signal especially during functional electrical stimulation (FES)-evoked contractions. Hence, an accurate quantification of the relationship between the eEMG potential and FES-evoked muscle response remains elusive and continues to attract the attention of researchers due to its potential application in the fields of biomechanics, muscle physiology, and rehabilitation science. We conducted a systematic review to examine the effectiveness of eEMG potentials to assess muscle force and fatigue, particularly as a biofeedback descriptor of FES-evoked contractions in individuals with spinal cord injury. At the outset, 2867 citations were identified and, finally, fifty-nine trials met the inclusion criteria. Four hypotheses were proposed and evaluated to inform this review. The results showed that eEMG is effective at quantifying muscle force and fatigue during isometric contraction, but may not be effective during dynamic contractions including cycling and stepping. Positive correlation of up to r = 0.90 (p < 0.05) between the decline in the peak-to-peak amplitude of the eEMG and the decline in the force output during fatiguing isometric contractions has been reported. In the available prediction models, the performance index of the eEMG signal to estimate the generated muscle force ranged from 3.8% to 34% for 18 s to 70 s ahead of the actual muscle force generation. The strength and inherent limitations of the eEMG signal to assess muscle force and fatigue were evident from our findings with implications in clinical management of spinal cord injury (SCI) population.

Matched MeSH terms: Muscle, Skeletal/physiopathology*
Fulltext Surface electromyography signal processing and classification techniques

Chowdhury RH, Reaz MB, Ali MA, Bakar AA, Chellappan K, Chang TG

Sensors (Basel), 2013;13(9):12431-66.
PMID: 24048337 DOI: 10.3390/s130912431

Electromyography (EMG) signals are becoming increasingly important in many applications, including clinical/biomedical, prosthesis or rehabilitation devices, human machine interactions, and more. However, noisy EMG signals are the major hurdles to be overcome in order to achieve improved performance in the above applications. Detection, processing and classification analysis in electromyography (EMG) is very desirable because it allows a more standardized and precise evaluation of the neurophysiological, rehabitational and assistive technological findings. This paper reviews two prominent areas; first: the pre-processing method for eliminating possible artifacts via appropriate preparation at the time of recording EMG signals, and second: a brief explanation of the different methods for processing and classifying EMG signals. This study then compares the numerous methods of analyzing EMG signals, in terms of their performance. The crux of this paper is to review the most recent developments and research studies related to the issues mentioned above.

Matched MeSH terms: Muscle, Skeletal/physiology*
Fulltext A fuzzy controller for lower limb exoskeletons during sit-to-stand and stand-to-sit movement using wearable sensors

Reza SM, Ahmad N, Choudhury IA, Ghazilla RA

Sensors (Basel), 2014 Mar 04;14(3):4342-63.
PMID: 24599193 DOI: 10.3390/s140304342

Human motion is a daily and rhythmic activity. The exoskeleton concept is a very positive scientific approach for human rehabilitation in case of lower limb impairment. Although the exoskeleton shows potential, it is not yet applied extensively in clinical rehabilitation. In this research, a fuzzy based control algorithm is proposed for lower limb exoskeletons during sit-to-stand and stand-to-sit movements. Surface electromyograms (EMGs) are acquired from the vastus lateralis muscle using a wearable EMG sensor. The resultant acceleration angle along the z-axis is determined from a kinematics sensor. Twenty volunteers were chosen to perform the experiments. The whole experiment was accomplished in two phases. In the first phase, acceleration angles and EMG data were acquired from the volunteers during both sit-to-stand and stand-to-sit motions. During sit-to-stand movements, the average acceleration angle at activation was 11°-48° and the EMG varied from -0.19 mV to +0.19 mV. On the other hand, during stand-to-sit movements, the average acceleration angle was found to be 57.5°-108° at the activation point and the EMG varied from -0.32 mV to +0.32 mV. In the second phase, a fuzzy controller was designed from the experimental data. The controller was tested and validated with both offline and real time data using LabVIEW.

Matched MeSH terms: Muscle, Skeletal/physiology

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